The objective of this project is to study the mechanisms involved in androgen mediated gene expression inthe rat and mouse seminal vesicle. The genes for the major seminal vesicle secretion protein IV and V (SVS IV and V) are under detailed study. Bacterial clones have been identified and characterized which contain inserts for cDNAs SVS IV and SVS V from rats. The cDNA IV and V were shown to have unique sequences. Sequence comparisons show very little homology in the coding regions. A region, in the 3'-non-coding portion of the mRNA, is, however, almost 80% homologous. The androgen induction of IV and V mRNA in castrate rats was measured using the respective probes. The chromosomal genes for IV and V were isolated from a rat gene library and the SVS IV gene was shown to be about 1.9 kb with two introns. Another observation is that the SVS IV gene has an insertion of approximately 200 bp in the second intron. The insertion site is flanked by 20 bp direct repeats. A major repetitive element (100,000 copies/genome) was shown to be on the 3' end of the SVS IV gene. A palindromic structure at -117 bp from the CAP site was identified and shown to be S1-nuclease sensitive in the supercoiled state. DNase I and S1-nuclease sensitive sites in chromatin structure around the SVS IV gene are presently being defined.